in 30 to 40 percent of the population. Today it is found in
10 to 20 percent, a likely result of our diminished intake of
fermented foods and fiber, our reliance on ultra-processed
foods, and the rise in antibiotic use.^5 Considering that L.
reuteri would normally be transmitted in breast milk, it’s
like the friend we didn’t know we had until it was gone.
Optimizing Glutamate/GABA
One way of keeping this system functioning normally is
to embody the glutamatergic/GABAergic balance in your
own life, building in periods of deliberate excitation and
inhibition. Intense exercise has been shown to promote
balance, boosting both GABA and glutamate in the human
brain.^6 This effect lasts well beyond the workout, as it
correlates with higher resting levels of glutamate one week
later. Major depression is categorized as having reduced
levels of both, and exercise has been shown to improve
depressive symptoms. Exercise has also been shown to help
the brain more effectively metabolize glutamate, thus
reducing its buildup.^7
Meditation, yoga, and deep breathing exercises are
excellent ways of achieving increased GABA.^8
Hypothermic conditioning, either by taking an ice bath or
cold shower or by doing cryotherapy (where one enters a
tank filled with freezing nitrogen gas, usually for around
three minutes), is an excellent means of normalizing one’s
GABA/glutamatergic balance.^9 Though stressful and